light_world.lua/shader/refraction.glsl
2014-03-23 19:10:58 +01:00

19 lines
783 B
GLSL

extern Image backBuffer;
extern vec2 screen = vec2(800.0, 600.0);
extern float refractionStrength = 1.0;
vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords) {
vec2 pSize = vec2(1.0 / screen.x, 1.0 / screen.y);
vec4 normal = Texel(texture, texture_coords);
if(normal.a > 0.0) {
vec4 normalOffset = Texel(texture, vec2(texture_coords.x + (normal.x - 0.5) * pSize.x * refractionStrength, texture_coords.y + (normal.y - 0.5) * pSize.y * refractionStrength));
if(normalOffset.a > 0.0) {
return Texel(backBuffer, vec2(texture_coords.x + (normal.x - 0.5) * pSize.x * refractionStrength, texture_coords.y + (normal.y - 0.5) * pSize.y * refractionStrength));
} else {
return Texel(backBuffer, texture_coords);
}
} else {
return vec4(0.0);
}
}